Silica have been used in treads of tires to improve traction. Unfortunately, one consequence of their use is an undesirable increase in the weight of the tire.
Aerogels are characterized by very low densities, large open pores, and a high inner surface area. For example, SiO2 aerogels have a high transparency similar to glass, a thermal conductivity lower than to polystyrene or polyurethane foam and very high specific surface areas similar to charcoal. As a result of these properties, aerogels have been used for heat insulation, optical applications, sensors, catalysts or catalyst carriers.
U.S. Pat. No. 4,356,214 discloses a method of coating the inner surface of a pneumatic tire with a sealing material containing polybutene, polyisobutylene, an aerogel and powder rubber.
The present invention relates to a pneumatic tire having a tread containing from 1 to 150 phr of a metal oxide aerogel.